Contribution Folders may be created and accessed via WebDAV. WebDAV is an alternative protocol to checking-in documents through the browser or Site Studio interface. When you create the folder you specify the metadata you want items in the folder to have upon check-in. Then you can connect to these folders via WebDAV.
You can connect via any program that can create a WebDAV connection. Both Windows and Mac OS X have this capability built in, but other WebDAV clients also work. Note, however, that there is a known bug with setting up the WebDav connection directly from Windows 7 using the "map network drive..." option; we recommend using a standalone WebDav client instead (e.g., BitKinex, available for free from BitKinex).
Some possible uses are batchloading a bunch of documents, or getting desktop access to your files to do searching or code cleanup.